CN105823398B - A new type of minimum bending radius test device and method for flexible umbilical cables in marine engineering - Google Patents

Abstract

The present invention discloses a novel device for testing the minimum bending radius of flexible cables in marine engineering, comprising an anvil, a horizontal slide rail, a rack located on the horizontal slide rail, an actuator for pushing the rack to move along the horizontal slide rail, a pinion matched with the rack, a large gear matched with the pinion, a gear fixing frame for fixing the large gear and the pinion, and a rope. The anvil comprises an arc plate, a cable bending support plate for fixing the arc plate, and a supporting truss structure. The present invention also discloses a novel method for testing the minimum bending radius of flexible cables in marine engineering. The present invention realizes that during the loading process, the cable gradually and continuously transitions from a larger radius of curvature to a smaller radius until the cable armored wire reaches a yield state. Thereby, it is ensured that the minimum bending radius of the cable can be accurately obtained in the test.

Description

A new type of minimum bending radius test device for flexible umbilical cables in marine engineering and its method

technical field

The invention relates to a testing device and method, in particular to a novel testing device and method for the minimum bending radius of flexible umbilical cables in ocean engineering.

Background technique

my country's offshore oil and gas reserves are abundant, and most of them are distributed in deep waters such as the South China Sea. Submarine cables, umbilical cables and flexible pipelines are one of the indispensable equipment in deep sea oil and gas exploitation. Such equipment can be collectively referred to as marine flexible umbilicals, and its structure is usually composed of corresponding functional components and strengthening components such as armored steel wires. According to different engineering requirements, pipe cables with corresponding functions should be selected; submarine cables are mainly responsible for providing electrical energy for subsea oil production equipment, umbilical cables are mainly responsible for power, signal transmission and other related functions between floating bodies on the water and submarine equipment, and flexible pipes are mainly responsible for equipment. Oil and gas transportation between. During storage, transportation, installation and laying, and on-site operation of marine flexible umbilical cables, due to the influence of factors such as working load, floating body movement, and complex ocean environment, it is easy to cause a variety of mechanical behavior failures. Among them, when the bending radius of the umbilical cable under load is less than its minimum bending radius, the internal functions and load-bearing components of the umbilical cable will be damaged, which will affect the normal operation of the umbilical cable function. Therefore, the minimum bending radius of offshore engineering umbilical is one of the important design parameters. In order to verify whether the minimum bending radius of the umbilical cable product meets the design requirements, thereby reducing the probability of bending damage during use, the minimum bending radius of the umbilical cable needs to be tested and certified in the laboratory before service. The measurement results will be used as important mechanical performance indicators.

Due to the complex structure and variety of umbilical cables, the minimum bending radius of different types of umbilical cables varies greatly, and the range of variation is usually 1m to 4m. At present, the existing experimental equipment in the laboratory mainly conducts verification experiments for a specific radius range (near the minimum bending radius of the umbilical cable), which is not suitable for every kind of umbilical cable, and cannot achieve continuous and accurate measurement. According to market research, it is found that no manufacturer has produced this type of testing machine so far. Therefore, most umbilical cable manufacturers or research institutions use self-made experimental devices to test the minimum bending radius according to the test objects.

According to actual engineering needs, the minimum bending radius is often used to simulate the state of marine engineering flexible umbilical cables stored on reels or drums. Therefore, the minimum bending radius test equipment needs to include equipment that simulates the roll, and equipment that can apply a bending moment to cause bending deformation. In addition, the experimental process needs to be configured with measuring equipment, such as strain gauges or sensors, in order to extract relevant parameters (intermediate or direct physical quantities) of the umbilical cable bending process. The experimental process of the minimum bending radius test of the umbilical cable is usually carried out in the following steps: sampling, fixing, laying, loading, measuring and post-processing. Before the experiment starts, it is necessary to formulate the corresponding test plan and select the umbilical cable samples, then fix the umbilical cable to be tested on the test frame, arrange the strain gauges at the test position according to the experimental requirements, and connect them to the data acquisition equipment. After ensuring that the above operations are correct, start the loading device and collect relevant data in real time. Finally, analyze and process the obtained data and form a perfect experiment report.

Defects or Problems Existing in Existing Technologies

At present, the semicircular anvil is used in the laboratory to carry out the minimum bending radius test of the umbilical cable (Fig. 1), which is mainly achieved through the following steps:

1. Theoretical estimation of the minimum bending radius of the umbilical cable 1` to be tested, or refer to the design value of the minimum bending radius of the molded product;

2. Compare the theoretical estimated value (or design value) with the existing bending radius on the anvil 2` (Fig. 2-Fig. 4), and select the larger bending radius that the anvil 2` that is closest to it can provide. Test, and then insert iron rods in the corresponding holes and fix them with bolts;

3. Place the umbilical cable 1` on the anvil 2` with a selected radius, and arrange strain gauges at the corresponding positions and carry out debugging;

4. Lift the anvil 2` through the chain hoist 3` and the transmission device, and at the same time fix the two ends of the umbilical cable 1` to be tested by chain traction. With the gradual rise of the anvil 2`, the umbilical 1` is gradually attached to the anvil 2` until it is completely attached, and the strain value at this time is recorded;

5. Compare the strain value with the allowable strain of the component, usually the value is less than the allowable strain, then adjust the bending radius of the anvil 2` to a smaller value, and continue the test until the strain value is greater than the allowable strain . Therefore, the value range of the minimum bending radius of the umbilical cable 1' is finally estimated.

This kind of experimental device has many disadvantages:

1. The minimum bending radius of the umbilical cable that can be measured by the anvil has the disadvantage of jumping in a small range, which is only suitable for the measurement of the minimum bending radius of some umbilical cables, and the measurement results are not accurate;

2. Depending on the loading method of the chain hoist, manual force can only be applied intermittently; thus the loading speed cannot be well controlled. At the same time, due to the structural characteristics of the chain block, there will be a certain rebound after each force is applied, which brings great inconvenience to the later data processing;

3. Since the joints at both ends of the pipe cable are fixed by chain traction, a certain range of swings will occur during the loading process, and the stability is poor, which increases the error of the experiment;

4. The entire test operation requires the cooperation of multiple people to complete, which is time-consuming and laborious;

5. Since the umbilical cable test piece needs to span the entire anvil, a longer test piece is required to facilitate loading and operation, resulting in waste of experimental samples.

Contents of the invention

Aiming at the above problems, a new type of testing device and method for the minimum bending radius of flexible umbilical cables in marine engineering is proposed. The test device is designed with an arc plate with a linear change in the radius of curvature, and at the same time, an actuator is used instead of a chain hoist for loading. The design of the test device can meet the measurement of the minimum bending radius of most umbilical cables. The technical means adopted in the present invention are as follows:

A new type of minimum bending radius test device for flexible umbilical cables in marine engineering, including an anvil, a horizontal slide rail, a rack located on the horizontal slide rail, and an actuation for pushing the rack to move along the horizontal slide rail device, a pinion cooperating with the rack, a bull gear cooperating with the pinion, a gear holder and a rope for fixing the bull gear and the pinion,

The anvil includes an arc plate, a pipe cable bending support plate and a supporting truss structure for fixing the arc plate,

The gear end surface on one side of the bull gear has a cylindrical winding part coaxial with the bull gear, and one end of the rope is fixed on the side wall of the cylindrical winding part,

The radius of curvature of the outer edge of the horizontal section of the arc plate changes linearly, and the end of the arc plate with a large radius of curvature is fixedly connected to the bending support plate of the pipe cable. A horizontal through hole extending in the bending direction, the horizontal through hole extends to the bending support plate of the pipe cable, and the side of the bending support plate of the pipe cable near the outer edge of the arc plate is provided with a joint fixing device,

In the working state, when there is no loading force, one end of the umbilical cable is vertically connected to the joint fixing device through the umbilical cable joint, and the other end of the rope is connected to the free end of the umbilical cable through the horizontal through hole , the center line of the rope and the center line of the umbilical are located in the same horizontal plane (that is, the loading surface is always kept on the same plane), and when the umbilical is not bent, the fixed end of the umbilical and the tangent at the opening of the horizontal via,

When force is applied, the actuator pushes the rack, the rack drives the pinion, the pinion drives the bull gear, and the bull gear rotates so that the rope is wound around the cylindrical On the side wall of the winding part, the rope pulls the umbilical to bend toward the horizontal through hole.

The radius of curvature at a certain point on the outer edge of the horizontal section of the arc plate satisfies the following formula:

ρ=-1.5x+4,

Establish a rectangular coordinate system xOy in the horizontal plane where the horizontal section of the arc plate is located, wherein the intersection of the outer edge of the horizontal section of the arc plate and the curved support plate of the umbilical cable is the coordinate origin O, perpendicular to the umbilical cable The curved support plate and pointing to the extension direction of the arc plate is the positive direction of the x-axis, the curved support plate parallel to the pipe cable and pointing to the bending direction of the arc plate is the positive direction of the y-axis, and ρ is the horizontal section of the arc plate The radius of curvature at a certain point on the outer edge of the arc plate, x is the value corresponding to a certain point on the x-axis on the outer edge of the horizontal section of the arc plate, 0≤x≤2, and the range of x is suggested by the present invention scope of use.

in, but Assuming the initial condition y(0)=0, y′(0)=0, using MAPLE to solve the differential equation, the analytical solution is obtained as:

Wherein, i is an imaginary number, t is an integral variable, and the above equation y (x) is the curve equation of the outer edge of the horizontal section of the arc plate, and the outer edge of the horizontal section of the arc plate is obtained according to the above equation y (x) The curve is processed.

The gear fixing frame is provided with two vertically arranged through slots, and the two through slots are respectively connected to the fixed plate I and the fixed plate II through bolts and nuts, and the fixed plate I is connected to the large shaft through the gear shaft I. Gear connection, the fixed plate II is connected with the pinion through the gear shaft II.

The surface of the arc plate located below the horizontal through hole is provided with a plurality of connecting holes of the pipe cable support rods arranged along the bending direction of the arc plate, and the connection holes of the pipe cable support rods are provided with The cable keeps the horizontal cable support rod, and the cable support rod is connected with the connecting hole of the cable support rod through bolts and nuts.

In order to facilitate the testing of umbilical cables with various pipe diameters, the connecting hole of the umbilical cable support rod is a vertically extending hole, which is convenient for the adjustment of the connection position of the umbilical cable support rod and the connection hole of the umbilical cable support rod, and then The position of the upper edge of the umbilical cable support rod is adjusted to support the umbilical cables with different pipe diameters.

The bull gear is provided with a plurality of holes I evenly distributed around the axis of the bull gear, and the holes I pass through the gear end surface of the bull gear and the end surface of the cylindrical winding part,

The pinion is provided with a plurality of holes II evenly distributed around the axis of the pinion, and the holes II pass through the gear end surface of the pinion.

The detection device also includes a support platform, on which the bending support plate of the umbilical cable and the arc plate are arranged.

The upper edge of the arc plate is provided with a radius of curvature.

The invention also discloses a novel method for testing the minimum bending radius of flexible umbilical cables in marine engineering, which is characterized in that it has the following steps:

S1. Design a new type of minimum bending radius test device for flexible pipe cables in marine engineering as described above;

S2. Connect one end of the umbilical cable vertically to the joint fixing device through the umbilical cable joint, connect the free end of the umbilical cable to the rope, and the rope passes through the horizontal through hole and is wound around the on the side wall of the cylindrical winding part;

S3. Open a plurality of densely arranged openings on the busbar of the umbilical cable farthest from the arc plate, which can leak the armored steel wires inside the umbilical cable and accommodate the strain gauges. The strain gauge is bonded to the armored steel wire, and at the same time, one end of the cable connected to the strain gauge is fixed on the pipe cable with an adhesive tape, so as to prevent the distortion of the test data due to the shaking of the cable during the test. fluctuation, the other end of the cable is connected to the acquisition system to realize real-time transmission of stress and strain data;

S4. By adjusting the minimum bending radius test device of a new offshore engineering compliance umbilical cable so that the centerline of the rope and the centerline of the umbilical cable are located in the same horizontal plane, preventing the rope stretching process The strain value measured in is not the maximum strain value, produces measurement error, simultaneously, makes described rope be in tension state all the time, guarantees that described test device can run smoothly during the experiment;

S5. Carry out small-scale loading on the umbilical cable through the driving of the actuator, analyze the curve of the collected strain changing with time, complete the preliminary debugging of the entire test system, and carry out experiments in groups after the test requirements are met;

S6. Set the propulsion speed of the actuator, and realize quasi-static loading on the umbilical cable through gear transmission drive. As the load increases, the umbilical cable gradually bends toward the horizontal through hole, and Gradually close to the arc plate bending deformation, when the strain of one of the strain gauges on the armored steel wire reaches the yield strain, record the bending radius corresponding to the cut point of the umbilical cable and the arc plate at this time;

S7. Step S6 is repeated to perform statistics and error analysis on the bending radii obtained from multiple tests to obtain the minimum bending radius of the umbilical cable.

In the step S1, the height of the arc plate is 0.8m, the thickness of the arc plate is 0.1m, the median line of the horizontal through hole is 0.4m away from the lower edge of the arc plate, and the horizontal through hole The width of the hole is 0.08m. On the one hand, it is ensured that the rope can pass through the horizontal through hole without friction with the arc plate during the experiment. On the other hand, the width of the horizontal through hole should be small enough to reduce the The influence of the small opening on the experimental measurement results can reduce the stress concentration of the umbilical in contact with the horizontal through hole during the experiment. The opening of the side of the horizontal through hole close to the umbilical has rounded corners to further avoid stress concentration.

In the step S1, the pinion gear and the large gear are selected through conversion based on the bending stiffness of common umbilical cables, and the size of a single tooth is reduced to meet the requirement of continuous change when tension is applied.

The present invention has the following advantages:

1. Compared with the original anvil with a jumping radius of curvature, the present invention replaces the existing anvil by designing an arc plate with a linear change in curvature radius, so that the umbilical cable gradually and continuously transitions from a larger radius of curvature to Smaller radii until the umbilical armor wires reach yield. Thus, it is ensured that the test can accurately obtain the minimum bending radius of the umbilical.

2. A truss is set on the inner edge of the arc plate to ensure the structural strength and rigidity requirements of the arc plate itself, and to realize the loading test requirements of large-diameter pipe cables.

3. The arc plate is provided with a horizontal through hole extending along the bending direction of the arc plate. The rope passes through it and loads the pipe cable, which makes loading more flexible and convenient, and ensures that the loading surface is always kept on the same plane.

4. Compared with chain hoist loading, the present invention uses the actuator to drive the rack to complete the rotation of the large and small gears, and then pulls the free end of the umbilical cable to realize the loading of the bending moment. This loading method is more convenient and labor-saving And easy to control.

5. Compared with the semicircular anvil test method, the present invention only needs half the length of the original umbilical test piece to meet the measurement requirements, saving sample consumption.

6. Amplify the stroke of the actuator through the large and small gears (two-stage gears), so as to realize a large displacement of the free end of the umbilical cable and a large range of changes in the bending radius of curvature to accurately determine the value of the minimum bending radius.

7. When processing gears, a series of parameters such as tooth width and tooth thickness can be selected and designed, so that the minimum bending radius test of the umbilical cable can achieve quasi-static loading and ensure the accuracy of the experimental measurement.

8. Through the setting of hole I and hole II, the material is saved and the structural strength of the large and small gears is also ensured.

9. Compared with the original experimental device, the personnel arrangement is greatly reduced, and the experimental cost is lower.

Based on the above reasons, the present invention can be widely promoted in fields such as performance testing.

Description of drawings

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Fig. 1 is a structural schematic diagram of an existing test device.

Fig. 2 is a front view of an anvil of a conventional test device.

Fig. 3 is a left side view of Fig. 2 .

FIG. 4 is a top view of FIG. 2 .

Fig. 5 is a schematic diagram of the spatial structure of a new type of minimum bending radius testing device for flexible umbilical cables in marine engineering in a specific embodiment of the present invention.

Fig. 6 is a front view of a new type of minimum bending radius testing device for flexible umbilical cables in marine engineering in a specific embodiment of the present invention.

Fig. 7 is a left side view of Fig. 6 .

FIG. 8 is a top view of FIG. 6 .

Fig. 9 is a front view of the large gear in the embodiment of the present invention.

Fig. 10 is a left side view of Fig. 9 .

FIG. 11 is a top view of FIG. 10 .

Fig. 12 is a schematic diagram of an anvil in a specific embodiment of the present invention.

Fig. 13 is a left side view of Fig. 12 .

FIG. 14 is a top view of FIG. 12 .

Detailed ways

Example 1

As shown in Figure 5-Figure 14, a new type of minimum bending radius test device for flexible umbilical cables in marine engineering,

It includes an anvil, a horizontal slide rail 2, a rack 3 positioned on the horizontal slide rail 2, an actuator 4 that pushes the rack 3 to move along the horizontal slide rail 2, and an actuator 4 that cooperates with the rack 3. The pinion 5, the bull gear 6 cooperating with the pinion 5, the gear holder 7 and the rope 9 for fixing the bull gear 6 and the pinion 5,

The anvil comprises an arc plate 1, a pipe cable bending support plate 8 and a supporting truss structure 20 for fixing the arc plate 1,

The gear end surface on one side of the bull gear 6 has a cylindrical winding part 10 coaxial with the bull gear 6, and one end of the rope 9 is fixed on the side wall of the cylindrical winding part 10,

The radius of curvature of the outer edge of the horizontal section of the arc plate 1 changes linearly, and the end of the arc plate 1 with a large radius of curvature is fixedly connected to the bending support plate 8 of the pipe cable. The horizontal through hole 11 extending in the bending direction of the arc plate 1, the horizontal through hole 11 extends to the bending support plate 8 of the pipe cable, and the bending support plate 8 of the pipe cable is close to the side of the outer edge of the arc plate 1 A joint fixing device 12 is provided,

In the working state, when there is no loading force, one end of the umbilical cable 13 is vertically connected to the joint fixing device 12 through the umbilical cable joint, and the other end of the rope 9 passes through the horizontal through hole 11 to connect with the umbilical cable 9. 13, the center line of the rope 9 and the center line of the umbilical cable 13 are located in the same horizontal plane, and when the umbilical cable 13 is not bent, the fixed end of the umbilical cable 13 is connected to the horizontal channel The opening of hole 11 is tangent,

When force is applied, the actuator 4 pushes the rack 3, the rack 3 drives the pinion 5, the pinion 5 drives the bull gear 6, and the bull gear 6 rotates so that the The rope 9 is wound on the side wall of the cylindrical winding part 10 , and the rope 9 pulls the umbilical 13 to bend toward the horizontal through hole 11 .

The radius of curvature at a certain point on the outer edge of the horizontal section of the arc plate 1 satisfies the following formula:

ρ=-1.5x+4,

A rectangular coordinate system xOy is established in the horizontal plane where the horizontal section of the arc plate 1 is located, wherein the intersection of the outer edge of the horizontal section of the arc plate 1 and the curved support plate 8 of the pipe cable is the coordinate origin O, perpendicular to the The bending support plate 8 of the pipe cable and pointing to the arc plate 1 is the positive direction of the x-axis, the bending direction parallel to the bending support plate 8 of the pipe cable and pointing to the arc plate 1 is the positive direction of the y-axis, and ρ is The radius of curvature at a certain point on the outer edge of the horizontal section of the arc plate 1, x is the value corresponding to a certain point on the outer edge of the horizontal section of the arc plate 1 on the x-axis, 0≤x≤2.

The gear fixing frame 7 is provided with two vertically arranged through grooves 15, and the two through grooves 15 are respectively connected to the fixed plate I16 and the fixed plate II17 through bolts and nuts, and the fixed plate I16 is connected to the fixed plate I18 through the gear shaft I18. The large gear 6 is connected, and the fixed plate II17 is connected with the pinion 5 through a gear shaft II19.

The surface of the arc plate 1 located below the horizontal through hole 11 is provided with a plurality of connecting holes 21 arranged along the bending direction of the arc plate 1. There is an umbilical cable support rod 22 supporting the umbilical cable 13 to keep it horizontal, and the umbilical cable support rod 22 is connected to the connection hole 21 of the umbilical cable support rod through bolts and nuts.

The bull gear 6 is provided with a plurality of holes I23 evenly distributed with the axis of the bull gear 6 as the axis, and the holes I23 run through the gear end surface of the bull gear 6 and the end surface of the cylindrical winding part 10,

The pinion 5 is provided with a plurality of holes II 24 evenly distributed around the axis of the pinion 5 , and the holes II 24 pass through the gear end surface of the pinion 5 .

The detection device also includes a support platform 14 on which the umbilical bending support plate 8 and the arc plate 1 are arranged.

The upper edge of the arc plate 1 is provided with a radius of curvature.

Example 2

A new method for testing the minimum bending radius of flexible umbilical cables in marine engineering has the following steps:

S1, design a kind of novel marine engineering compliance pipe cable minimum bending radius testing device as described in embodiment 1;

S2. Connect one end of the umbilical cable 13 vertically to the joint fixing device 12 through the umbilical cable joint, the free end of the umbilical cable 13 is connected to the rope 9, and the rope 9 passes through the horizontal through hole 11, and wound on the side wall of the cylindrical winding part 10;

S3. On the busbar of the umbilical cable 13 farthest from the arc plate 1, a plurality of openings are densely arranged, capable of leaking the armored steel wire inside the umbilical cable 13, and capable of accommodating strain gauges, Bond the strain gage to the armored steel wire with glue, and fix one end of the cable connected to the strain gage to the umbilical cable 13 with adhesive tape, and connect the other end of the cable to the acquisition system , realizing real-time transmission of stress and strain data;

S4. By adjusting the minimum bending radius test device for a new type of marine engineering compliance umbilical cable, the center line of the rope 9 and the center line of the umbilical cable 13 are located in the same horizontal plane, and at the same time, the Rope 9 is always in tension;

S5. Drive the umbilical 13 through the actuator 4 to load the umbilical cable 13 in a small range, analyze the curve of the collected strain changing with time, and complete the preliminary debugging of the entire test system. After the test requirements are met, carry out experiments in groups ;

S6. Set the propulsion speed of the actuator 4, and realize the quasi-static loading of the umbilical 13 through gear transmission drive. As the load increases, the umbilical 13 gradually moves toward the horizontal through hole 11 bent, and gradually close to the bending deformation of the arc plate 1, when the strain of a certain strain gauge on the armored steel wire reaches the yield strain, record the distance between the umbilical 13 and the arc plate 1 at this time The bending radius corresponding to the tangent point;

S7 , repeating step S6 , performing statistics and error analysis on the bending radii obtained from multiple tests, and obtaining the minimum bending radius of the umbilical 13 .

In the step S1, the height of the arc plate 1 is 0.8m, the thickness of the arc plate 1 is 0.1m, and the median line of the horizontal through hole 11 is 0.4m away from the lower edge of the arc plate 1, so The width of the horizontal through hole 11 is 0.08m.

In the step S1, the pinion gear 5 and the bull gear 6 are selected through conversion based on the bending stiffness of common umbilical cables, and the size of a single tooth is reduced to meet the requirement of continuous change when tension is applied.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto, any person familiar with the technical field within the technical scope disclosed in the present invention, according to the technical solution of the present invention Any equivalent replacement or change of the inventive concepts thereof shall fall within the protection scope of the present invention.

Claims (8)

1. The utility model provides a novel ocean engineering compliance pipe cable minimum bend radius test device which characterized in that: comprises an anvil block, a horizontal sliding rail, a rack positioned on the horizontal sliding rail, an actuator for pushing the rack to move along the horizontal sliding rail, a pinion matched with the rack, a gearwheel matched with the pinion, a gear fixing frame for fixing the gearwheel and the pinion and a rope,

the anvil block comprises an arc plate, a pipe cable bending support plate for fixing the arc plate and a support truss structure,

the end surface of the gear at one side of the big gear is provided with a cylindrical winding part which is coaxial with the big gear, one end of the rope is fixed on the side wall of the cylindrical winding part,

the curvature radius of the outer edge of the horizontal section of the arc plate is changed linearly, one end with large curvature radius of the arc plate is fixedly connected with the pipe cable bending support plate, the arc plate is provided with a horizontal through hole extending along the bending direction of the arc plate, the horizontal through hole extends to the pipe cable bending support plate, one side of the pipe cable bending support plate, which is close to the outer edge of the arc plate, is provided with a joint fixing device,

the pipe cable bending support plate and the arc plate are arranged on the support table,

the upper edge of the arc plate is provided with a curvature radius value,

under the working state, when no force is loaded, one end of the tube cable is vertically connected with the connector fixing device through the tube cable connector, the other end of the rope penetrates through the horizontal through hole to be connected with the free end of the tube cable, the central line of the rope and the central line of the tube cable are positioned in the same horizontal plane, when the tube cable is not bent, the fixed end of the tube cable is tangent to the opening of the horizontal through hole,

when loading force is applied, the actuator pushes the rack, the rack drives the pinion, the pinion drives the large gear, the large gear rotates to enable the rope to be wound on the side wall of the cylindrical winding part, and the rope pulls the pipe cable to be bent through the horizontal through hole.

2. The test device of claim 1, wherein: the curvature radius at a certain point on the outer edge of the horizontal section of the arc plate satisfies the following formula:

ρ＝-1.5x+4，

set up rectangular coordinate system xOy in the horizontal plane of the horizontal cross section place of arc board, wherein, the outer edge of the horizontal cross section of arc board with the crossing department of the crooked backup pad of pipe cable is original point of coordinates O, perpendicular to the crooked backup pad of pipe cable just points to the positive direction that arc board extending direction is the x axle is on a parallel with the crooked backup pad of pipe cable just points to the crooked direction of arc board is y axle positive direction, and rho is the radius of curvature of certain point department on the outer edge of the horizontal cross section of arc board, x are the value that certain point corresponds on the x axle is followed to the outer edge of the horizontal cross section of arc board, and 0 is not less than 0 x and is not more than 2.

3. The test device of claim 1, wherein: the gear fixing frame is provided with two through grooves which are vertically arranged, the two through grooves are respectively connected with a fixing plate I and a fixing plate II through bolt and nuts, the fixing plate I is connected with the gear wheel through a gear shaft I, and the fixing plate II is connected with the pinion through a gear shaft II.

4. The test device of claim 1, wherein: the arc plate is located be equipped with a plurality of edges on the face of horizontal through-hole below the arc plate crooked direction range the pipe cable bracing piece connecting hole, be equipped with the support on the pipe cable bracing piece connecting hole the pipe cable keeps the horizontally pipe cable bracing piece, the pipe cable bracing piece pass through bolt and nut with pipe cable bracing piece connecting hole is connected.

5. The test device of claim 1, wherein: the bull gear is provided with a plurality of holes I which are uniformly distributed by taking the axis of the bull gear as an axis, the holes I penetrate through the gear end face of the bull gear and the end face of the cylindrical winding part,

the pinion is provided with a plurality of holes II which are uniformly distributed by taking the axis of the pinion as an axis, and the holes II penetrate through the gear end face of the pinion.

6. A novel method for testing the minimum bending radius of a flexible pipe cable of ocean engineering is characterized by comprising the following steps:

s1, designing a novel device for testing the minimum bending radius of the flexible pipe cable in ocean engineering according to any one of claims 1-5;

s2, vertically connecting one end of the umbilical with the joint fixing device through an umbilical joint, connecting the free end of the umbilical with the rope, and enabling the rope to pass through the horizontal through hole and to be wound on the side wall of the cylindrical winding part;

s3, opening a plurality of densely arranged openings which can leak out armor steel wires inside the pipe cable and can accommodate strain gauges on a bus of the pipe cable farthest from the arc plate, bonding the strain gauges on the armor steel wires through glue, fixing one end of a flat cable connected to the strain gauges on the pipe cable by using an adhesive tape, and connecting the other end of the flat cable with an acquisition system to realize real-time transmission of stress-strain data;

s4, adjusting the novel ocean engineering flexibility pipe cable minimum bending radius testing device to enable the central line of the rope and the central line of the pipe cable to be located in the same horizontal plane, and enabling the rope to be in a tension state all the time;

s5, carrying out small-amplitude loading on the pipe cable through the driving of the actuator, analyzing the curve of the acquired strain along with the change of time, completing the preliminary debugging of the whole test system, and carrying out experiments in groups after the test requirements are met;

s6, setting the propelling speed of the actuator, realizing quasi-static loading on the pipe cable through gear transmission driving, gradually bending the pipe cable towards the horizontal through hole along with the continuous increase of load, gradually clinging to the arc plate for bending deformation, and recording the bending radius corresponding to the contact point of the pipe cable and the arc plate when the strain of one strain gauge on the armored steel wire reaches the yield strain;

and S7, repeating the step S6, and performing statistics and error analysis on the bending radius obtained by multiple tests to obtain the minimum bending radius of the pipe cable.

7. The method of claim 6, wherein: in the step S1, the height of the arc plate is 0.8m, the thickness of the arc plate is 0.1m, the distance between the median line of the horizontal through hole and the lower edge of the arc plate is 0.4m, and the width of the horizontal through hole is 0.08 m.

8. The method of claim 6, wherein: in step S1, the pinion gear and the bull gear are scaled and selected by the bending stiffness of the umbilical, and the size of the single tooth is reduced to meet the requirement of continuous change when tension is applied.